I have an Ariens ZOOM 1640 I bought in the spring. When I replaced the blades in the spring, I also adjusted the tracking. I did get it tracking straight forward, however it set the tracking off in reverse, which makes doing zero turns more difficult.

Today I was changing the blades again and fooling around with the tracking to try to get both forward and back tracking straight. I can't for the life me figure it out. From what I can tell there are two possible adjustments.

One is the nuts that connect the linkage to the hydrogear. The other is a screw where the linkage connects to the lever. I can't seem to find any kind of adjustment to increase the top-end forward and slow down the reverse. Any ideas? Or does anyone have the service manual for the 1640?